Machitidwe osungira zinthu masiku ano samangokulira pa terabits zokha komanso ali ndi kuchuluka kwa data, komanso amafunikira mphamvu zochepa ndipo amakhala ndi malo ochepa. Machitidwewa amafunikanso kulumikizana bwino kuti apereke kusinthasintha kwakukulu. Opanga mapulogalamu amafunika kulumikizana kochepa kuti apereke kuchuluka kwa data komwe kumafunika lero kapena mtsogolo. Ndipo chikhalidwe kuyambira kubadwa mpaka kukula ndi kukula pang'onopang'ono sichili ntchito ya tsiku ndi tsiku. Makamaka mumakampani a IT, ukadaulo uliwonse ukusintha nthawi zonse ndikusintha wokha, monga momwe zilili ndi Serial Attached SCSI (SAS). Monga wolowa m'malo mwa SCSI yofanana, SAS specification yakhalapo kwa nthawi ndithu.
M'zaka zomwe SAS yadutsamo, ma specifications ake asinthidwa, ngakhale kuti protocol yoyambira yasungidwa, kwenikweni palibe kusintha kwakukulu, koma ma specifications a external interface connector asintha kwambiri, zomwe ndi kusintha komwe kwapangidwa ndi SAS kuti igwirizane ndi malo amsika, ndi "masitepe owonjezerawa kufika pa makilomita chikwi" kusintha kosalekeza, ma specifications a SAS akukula kwambiri. Ma interface connectors a ma specifications osiyanasiyana amatchedwa SAS, ndipo kusintha kuchokera ku parallel kupita ku serial, kuchokera ku parallel SCSI technology kupita ku serial connected SCSI (SAS) technology kwasintha kwambiri njira yolumikizira ma cable. Parallel SCSI yakale ikhoza kugwira ntchito single-end kapena differential pa ma channel 16 mpaka 320Mb/s. Pakadali pano, SAS3.0 interface yomwe ndi yofala kwambiri m'munda wosungira ma enterprise ikugwiritsidwabe ntchito pamsika, koma bandwidth ndi yofulumira kawiri kuposa SAS3 yomwe sinasinthidwe kwa nthawi yayitali, yomwe ndi 24Gbps, pafupifupi 75% ya bandwidth ya common PCIe3.0×4 solid-state drive. Cholumikizira chaposachedwa cha MiniSAS chomwe chafotokozedwa mu SAS-4 ndi chaching'ono ndipo chimalola kuchuluka kwa mphamvu. Cholumikizira chaposachedwa cha Mini-SAS ndi theka la kukula kwa cholumikizira choyambirira cha SCSI ndipo 70% kukula kwa cholumikizira cha SAS. Mosiyana ndi chingwe choyambirira cha SCSI parallel, SAS ndi Mini SAS zonse zili ndi njira zinayi. Komabe, kuwonjezera pa liwiro lapamwamba, kuchuluka kwa mphamvu, komanso kusinthasintha kwakukulu, palinso kuwonjezeka kwa zovuta. Chifukwa cha kukula kochepa kwa cholumikizira, wopanga chingwe choyambirira, wosonkhanitsa chingwe, ndi wopanga makina ayenera kuyang'anitsitsa kwambiri magawo a umphumphu wa chizindikiro nthawi yonse yolumikizira chingwe.
Si onse osonkhanitsa mawaya omwe amatha kupereka ma signali apamwamba kwambiri kuti akwaniritse zosowa za ma signali abwino a makina osungiramo zinthu. Osonkhanitsa mawaya amafunika njira zabwino komanso zotsika mtengo zosungiramo zinthu zamakono. Kuti apange mawaya olimba komanso olimba amagetsi, zinthu zingapo ziyenera kuganiziridwa. Kuwonjezera pa kusunga bwino makina ndi kukonza, opanga ayenera kuyang'anitsitsa kwambiri magawo a ma signali abwino omwe amapangitsa kuti mawaya amakono amagetsi osungiramo zinthu azitheke.
Kufotokozera za umphumphu wa chizindikiro (Ndi chizindikiro chiti chomwe chatha?)
Zina mwa zinthu zazikulu zomwe zimapangitsa kuti chizindikiro chikhale cholondola ndi monga kutayika kwa chizindikiro, kulankhulana kwapafupi ndi kutali, kutayika kobwerera, kusokonekera kwa kusiyana kwa awiri mkati, komanso kutalika kwa kusiyana kwa chizindikiro kupita ku common mode. Ngakhale kuti zinthuzi zimagwirizana ndipo zimakhudzana, tikhoza kuganizira chinthu chimodzi nthawi imodzi kuti tiphunzire za mphamvu yake yaikulu.
Kutayika kwa kuyika (Ma parameter a pafupipafupi kwambiri Maziko 01- magawo a kuchepa)
Kutayika kwa chizindikiro kuchokera kumapeto otumizira chingwe kupita kumapeto olandirira, komwe kumagwirizana mwachindunji ndi mafupipafupi. Kutayika kwa chizindikiro kumadaliranso nambala ya waya, monga momwe zasonyezedwera pachithunzi cha attenuation pansipa. Pazigawo zamkati za chingwe cha 30 kapena 28-AWG, chingwe chabwino chiyenera kukhala ndi attenuation yochepera 2dB/m pa 1.5GHz. Pa 6Gb/s SAS yakunja pogwiritsa ntchito zingwe za 10m, chingwe chokhala ndi mzere wapakati wa 24 chimalimbikitsidwa, chomwe chili ndi attenuation ya 13dB yokha pa 3GHz. Ngati mukufuna malire ambiri a chizindikiro pamitengo yokwera ya data, tchulani chingwe chokhala ndi attenuation yocheperako pamafupipafupi apamwamba pa zingwe zazitali.
Crosstalk (Maziko a Ma Parameters Othamanga Kwambiri 03- Ma parameter a Crosstalk)
Kuchuluka kwa mphamvu yotumizidwa kuchokera ku chizindikiro chimodzi kapena kusiyana kwa mawaya kupita ku china. Pa zingwe za SAS, ngati crosstalk yapafupi (NEXT) si yaying'ono mokwanira, imayambitsa mavuto ambiri olumikizirana. Muyeso wa NEXT umapangidwa kumapeto amodzi okha a chingwe, ndipo ndi kuchuluka kwa mphamvu yotumizidwa kuchokera ku signal yotulutsa kupita ku input receiving pair. Far-end crosstalk (FEXT) imayesedwa poika chizindikiro cha signal ya signal kumapeto ena a chingwe ndikuwona kuchuluka kwa mphamvu komwe kwatsala pa signal yotumizira kumapeto ena a chingwe.
Chotsatira mu chingwe ndi cholumikizira nthawi zambiri chimachitika chifukwa cha kusaleka bwino kwa mawiri a chizindikiro, zomwe zingachitike chifukwa cha malo otulutsira ndi mapulagi, kusakhazikika bwino, kapena kusagwira bwino ntchito kwa malo omalizira chingwe. Wopanga makina ayenera kuwonetsetsa kuti cholumikizira chingwe chathetsa mavuto atatuwa.
Ma curve otayika a zingwe zodziwika bwino za 100Ω za 24, 26, ndi 28
Kulumikiza chingwe kwabwino kwambiri motsatira "SFF-8410-Specification for HSS Copper Testing and Performance Requirements" komwe kunayesedwa kuti NEXT iyenera kukhala yochepera 3%. Ponena za s-parameter, NEXT iyenera kukhala yoposa 28dB.
Kutayika Kobwerera (Magawo Oyambira a Ma Frequency 06- Kutayika Kobwerera)
Kutayika kobwerera kumayesa kuchuluka kwa mphamvu zomwe zimawonetsedwa kuchokera ku makina kapena chingwe pamene chizindikiro chikulowetsedwa. Mphamvu yowonetsedwa iyi ikhoza kuyambitsa kuchepa kwa kuchuluka kwa chizindikiro kumapeto kwa chingwe cholandirira ndipo ingayambitse mavuto a umphumphu wa chizindikiro kumapeto kwa chotumizira, zomwe zingayambitse mavuto osokoneza maginito amagetsi kwa makina ndi opanga makina.
Kutayika kobwerera kumeneku kumachitika chifukwa cha kusagwirizana kwa impedance mu msonkhano wa chingwe. Pokhapokha ngati vutoli lili mosamala kwambiri, impedance ya chizindikiro sichingasinthe ikadutsa mu socket, plug ndi wire terminal, kotero kuti kusintha kwa impedance kuchepe. Muyezo wa SAS-4 wamakono wasinthidwa kufika pa impedance value ya ±3Ω poyerekeza ndi ±10Ω ya SAS-2, ndipo zofunikira za zingwe zabwino ziyenera kusungidwa mkati mwa kulekerera kwapadera kwa 85 kapena 100±3Ω.
Kupotoza kolakwika
Mu zingwe za SAS, pali kusokonekera kwa ma skew kuwirikiza kawiri: pakati pa ma pairs osiyana ndi mkati mwa ma pairs osiyana (chizindikiro chosiyana cha chiphunzitso cha umphumphu wa chizindikiro). M'malingaliro, ngati zizindikiro zingapo zalowetsedwa kumapeto kwa chingwe, ziyenera kufika kumapeto ena nthawi imodzi. Ngati zizindikirozi sizifika nthawi imodzi, izi zimatchedwa kusokonekera kwa chingwe, kapena kusokonezeka kwa delay-skew. Pa ma pairs osiyana, kusokonezeka kwa ma skew mkati mwa ma pairs osiyana ndi kuchedwa pakati pa mawaya awiri a ma difference pairs, ndipo kusokonezeka kwa ma skew pakati pa ma difference pairs ndi kuchedwa pakati pa ma seti awiri a ma difference pairs. Kusokonezeka kwakukulu kwa ma difference pairs kudzawonjezera kusiyana kwa chizindikiro chotumizidwa, kuchepetsa kukula kwa chizindikiro, kuonjezera nthawi yothamanga ndikuyambitsa mavuto osokoneza magetsi. Kusiyana kwa chingwe chabwino ndi kusokonezeka kwa mkati mwa skew kuyenera kukhala kochepera 10ps
Nthawi yotumizira: Novembala-30-2023
